Julie, a chimpanzee, decided one day to stick a piece of long grass into her ear.
Apparently she would do this quite often. Then she would carry on with her day-to-day activities: grooming, playing, resting…with a big piece of grass hanging out of her ear.
Was it some strange kind of fashion statement? What would possess a chimpanzee to stick a piece of grass into their ear?
What first came to my mind was how my son loves to have his ear cleaned out with a Q-tip. He says it “feels nice.” Maybe it feels nice to have a big piece of grass stuck in your ear?
The amazing thing was that some of the other chimpanzees who lived in the sanctuary with Julie started to stick grass in their ears, too.
Some researchers wrote an article about Julie and her fancy ear accoutrements in the journal Animal Cognition. They had over 700 hours of video footage of Julie and her chimp colleagues, and they watched for this grass-in-ear-behaviour. Julie did it most often, followed by Kathy, Val, and Julie’s son, Jack. The researchers call the grass-in-ear behaviour a “spontaneously emerged tradition.”
Julie has since passed away, but apparently her ear grass-fashion lives on.
Van Leeuwen, E. J. C., Cronin, K. A., & Haun, D. B. M. (2014). A group-specific arbitrary tradition in chimpanzees (Pan troglodytes). Animal Cognition, 17(6), 1421-1425. DOI: 10.1007/s10071-014-0766-8.